”SPECTRUM AND FREQUENCIES OF MUTATIONS IN THE GJB2 AND GJB6 GENES AMOMG 228 ARGENTINEAN PATIENTS WITH SENSORINEURAL NON-SYNDROMIC DEAFNESS”

DALAMÓN V, ELGOYHEN AB

Hixton-United Kingdom,

Congreso; 6th Molecular Biology of Hearing and Deafness Conference; 2007

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> <!-- /* Font Definitions */ @font-face {font-family:PMingLiU; panose-1:2 1 6 1 0 1 1 1 1 1; mso-font-alt:新細明體; mso-font-charset:136; mso-generic-font-family:auto; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:1 134742016 16 0 1048576 0;} @font-face {font-family:"@PMingLiU"; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:136; mso-generic-font-family:auto; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:1 134742016 16 0 1048576 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:PMingLiU; mso-ansi-language:ES-AR; mso-fareast-language:ZH-TW;} p.MsoPlainText, li.MsoPlainText, div.MsoPlainText {margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Courier New"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} @page Section1 {size:595.3pt 841.9pt; margin:42.55pt 49.55pt 70.85pt 42.55pt; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Approximately 1/1000 children are born with hearing impairment, half due to genetic causes. Autosomal recessive non-syndromic sensorineural hearing impairment (ARNSHI) comprises 80% of cases. Mutations in the GJB2 gene, encoding connexin 26, are the major cause in the Caucasian population. The aim of this study was to investigate and report the spectrum and frequency of mutations in GJB2, GJB6 and OTOF, in deaf patients from Argentina. A total of 369 samples were analyzed; 228 from non-syndromic unrelated patients diagnosed with sensorineural hearing loss (18 cochlear implanted), and 141 from relatives and siblings. Mutations in GJB2 and GJB6 were found in 32% of patients; heterozygous state in 18.4% and homozygous and compound heterozygous in 13.6%. Overall 27 different sequence variations were identified. The mutation c.35delG accounted for 11% of the patients, resulting in 37% of the detected mutations, being the most frequent causing mutation in our population. Only 3% of mutations were detected in the GJB6 gene (del(GJB6-D13S1830) and del(GJB6-D13S1854)). None of the samples showed mutations in OTOF. In addition, 26 sequence variations different from c.35delG, were identified in the GJB2 gene, some are: T8M, G12V, V27I, M34T, V37I, E47X, 167delT, R75W, W77R, I82M, F83L, L90P, V95M, c.333delAA, R127H, E129K, R143W, V153I, M163V, M163L, R184P, IVS1+1G>A. The present study demonstrates that different mutations in the GJB2 and GJB6 genes are prevalent in our Argentinean population. These findings strengthen the importance of genetic screening in hearing-impaired patients for the contribution towards an adequate genetic counseling and treatment planning.